scholarly journals STING Agonists Induce an Innate Antiviral Immune Response against Hepatitis B Virus

2014 ◽  
Vol 59 (2) ◽  
pp. 1273-1281 ◽  
Author(s):  
Fang Guo ◽  
Yanxing Han ◽  
Xuesen Zhao ◽  
Jianghua Wang ◽  
Fei Liu ◽  
...  
Keyword(s):  
Immune Response ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cytokine Response ◽  
Hbv Infection ◽  
Stable Cell Line ◽  
Type I ◽  
Antiviral Immune Response ◽  
Hbv Replication ◽  
B Virus

ABSTRACTChronicity of hepatitis B virus (HBV) infection is due to the failure of a host to mount a sufficient immune response to clear the virus. The aim of this study was to identify small-molecular agonists of the pattern recognition receptor (PRR)-mediated innate immune response to control HBV infection. To achieve this goal, a coupled mouse macrophage and hepatocyte culture system mimicking the intrahepatic environment was established and used to screen small-molecular compounds that activate macrophages to produce cytokines, which in turn suppress HBV replication in a hepatocyte-derived stable cell line supporting HBV replication in a tetracycline-inducible manner. An agonist of the mouse stimulator of interferon (IFN) genes (STING), 5,6-dimethylxanthenone-4-acetic acid (DMXAA), was found to induce a robust cytokine response in macrophages that efficiently suppressed HBV replication in mouse hepatocytes by reducing the amount of cytoplasmic viral nucleocapsids. Profiling of cytokines induced by DMXAA and agonists of representative Toll-like receptors (TLRs) in mouse macrophages revealed that, unlike TLR agonists that induced a predominant inflammatory cytokine/chemokine response, the STING agonist induced a cytokine response dominated by type I IFNs. Moreover, as demonstrated in an HBV hydrodynamic mouse model, intraperitoneal administration of DMXAA significantly induced the expression of IFN-stimulated genes and reduced HBV DNA replication intermediates in the livers of mice. This study thus proves the concept that activation of the STING pathway induces an antiviral cytokine response against HBV and that the development of small-molecular human STING agonists as immunotherapeutic agents for treatment of chronic hepatitis B is warranted.

scholarly journals Plasmacytoid dendritic cells and their role in the immunopathogenesis of viral infections for example hepatitis B

2019 ◽  
Vol 11 (2) ◽  
pp. 14-19 ◽  
Author(s):  
R. R. Khodzhibekov ◽  
O. N. Khokhlova ◽  
A. R. Reizis ◽  
G. M. Kozhevnikova
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Infection ◽  
Unique Type ◽  
Antiviral Immune Response ◽  
Chronic Hbv Infection ◽  
B Virus ◽  
Chronic Hbv

A new approach in understanding the mechanisms of immune response in viral hepatitis is the discovery of a unique type of immune cells – plasmocytoid dendritic cells (pDCs). Plasmocytoid dendritic cells (pDCs) are cells of lymphoid origin and morphologically resemble plasma cells. Functionally, they are professional IFN-a-producing cells that play an important role in antiviral immune response. Data on the mechanisms of PDCs participation in hepatitis B virus infection are few and contradictory. In chronic HBV infection, the role of pDCs remains mysterious and poorly understood with conflicting circulating blood pDCs results that show differently that they are not affected or reduced. However, functional disorders of pDCs were observed in patients with chronic HBV infection. The establishment of these mechanisms, as well as the search for the cause of hepatitis B virus latency and the formation of chronic infection remains one of the important and promising areas of scientific activities today.

How Far we are towards Eradication of HBV Infection

2015 ◽  
Vol 24 (4) ◽  
pp. 473-479 ◽  
Author(s):  
Mihai Voiculescu
Keyword(s):  
Immune Response ◽  
Hepatitis B Virus ◽  
T Cell ◽  
Hepatitis B ◽  
T Cell Receptors ◽  
Hepatitis B Surface Antigen ◽  
Hbv Infection ◽  
Major Health Problem ◽  
Cell Receptors ◽  
B Virus

Hepatitis B virus (HBV) infection is a major health problem with an important biological and a significant socio-economic impact all over the world. There is a high pressure to come up with a new and more efficient strategy against HBV infection, especially after the recent success of HCV treatment. Preventing HBV infection through vaccine is currently the most efficient way to decrease HBV-related cirrhosis and liver cancer incidence, as well as the best way to suppress the HBV reservoir. The vaccine is safe and efficient in 80-95% of cases. One of its most important roles is to reduce materno-fetal transmission, by giving the first dose of vaccine in the first 24 hours after birth. Transmission of HBV infection early in life is still frequent, especially in countries with high endemicity.Successful HBV clearance by the host is immune-mediated, with a complex combined innate and adaptive cellular and humoral immune response. Different factors, such as the quantity and the sequence of HBV epitope during processing by dendritic cells and presenting by different HLA molecules or the polymorphism of T cell receptors (TOL) are part of a complex network which influences the final response. A new potential therapeutic strategy is to restore T-cell antiviral function and to improve innate and adaptive immune response by immunotherapeutic manipulation.It appears that HBV eradication is far from being completed in the next decades, and a new strategy against HBV infection must be considered. Abbreviations: ALT: alanine aminotransferase; APC: antigen presenting cells; cccDNA: covalently closed circular DNA; HBIG: hepatitis B immunoglobulin; HbsAg: hepatitis B surface antigen; HBV: hepatitis B virus; HCC: hepatocellular carcinoma; CTL: cytotoxic T lymphocyte; IFN: interferon; NUC: nucleos(t)ide analogues; pg RNA: pre genomic RNA; TLR: toll-like receptors; TOL: T cell receptors.

Effect of zidovudine on hepatitis B virus (HBV) replication in patients with chronic HIV and HBV infection

1989 ◽  
Vol 9 ◽  
pp. S189
Author(s):  
P Marcellin ◽  
G Pialcux ◽  
PM Girard ◽  
N Bover ◽  
M Martinot ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Infection ◽  
Hbv Replication ◽  
B Virus

Characterization of the immune response to the hepatitis B virus X protein in acute and chronic HBV infection

1989 ◽  
Vol 9 ◽  
pp. S182
Author(s):  
M. Levrero ◽  
A. Franco ◽  
E. De Marzio ◽  
C. Balsano ◽  
M.L. Avantaggiati ◽  
...  
Keyword(s):  
Immune Response ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Infection ◽  
X Protein ◽  
Chronic Hbv Infection ◽  
B Virus ◽  
Chronic Hbv

scholarly journals Hepatitis B Virus-Encoded MicroRNA Controls Viral Replication

2017 ◽  
Vol 91 (10) ◽  
Author(s):  
Xi Yang ◽  
Hongfeng Li ◽  
Huahui Sun ◽  
Hongxia Fan ◽  
Yaqi Hu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Persistent Infection ◽  
Hepatoma Cell ◽  
Hbv Infection ◽  
Dependent Manner ◽  
Dna Virus ◽  
Hbv Replication ◽  
B Virus ◽  
Self Replication

ABSTRACT MicroRNAs (miRNAs) are a class of small, single-stranded, noncoding, functional RNAs. Hepatitis B virus (HBV) is an enveloped DNA virus with virions and subviral forms of particles that lack a core. It was not known whether HBV encodes miRNAs. Here, we identified an HBV-encoded miRNA (called HBV-miR-3) by deep sequencing and Northern blotting. HBV-miR-3 is located at nucleotides (nt) 373 to 393 of the HBV genome and was generated from 3.5-kb, 2.4-kb, and 2.1-kb HBV in a classic miRNA biogenesis (Drosha-Dicer-dependent) manner. HBV-miR-3 was highly expressed in hepatoma cell lines with an integrated HBV genome and HBV+ hepatoma tumors. In patients with HBV infection, HBV-miR-3 was released into the circulation by exosomes and HBV virions, and HBV-miR-3 expression had a positive correlation with HBV titers in the sera of patients in the acute phase of HBV infection. More interestingly, we found that HBV-miR-3 represses HBsAg, HBeAg, and replication of HBV. HBV-miR-3 targets the unique site of the HBV 3.5-kb transcript to specifically reduce HBc protein expression, levels of pregenomic RNA (pgRNA), and HBV replication intermediate (HBV-RI) generation but does not affect the HBV DNA polymerase level, thus suppressing HBV virion production (replication). This may explain the low levels of HBV virion generation with abundant subviral particles lacking core during HBV replication, which may contribute to the development of persistent infection in patients. Taken together, our findings shed light on novel mechanisms by which HBV-encoded miRNA controls the process of self-replication by regulating HBV transcript during infection. IMPORTANCE Hepatitis B is a liver infection caused by the hepatitis B virus (HBV) that can become a long-term, chronic infection and lead to cirrhosis or liver cancer. HBV is a small DNA virus that belongs to the hepadnavirus family, with virions and subviral forms of particles that lack a core. MicroRNA (miRNA), a small (∼22-nt) noncoding RNA, was recently found to be an important regulator of gene expression. We found that HBV encodes miRNA (HBV-miR-3). More importantly, we revealed that HBV-miR-3 targets its transcripts to attenuate HBV replication. This may contribute to explaining how HBV infection leads to mild damage in liver cells and the subsequent establishment/maintenance of persistent infection. Our findings highlight a mechanism by which HBV-encoded miRNA controls the process of self-replication by regulating the virus itself during infection and might provide new biomarkers for diagnosis and treatment of hepatitis B.

New insight in the pathobiology of hepatitis B virus infection

Gut ◽  
2012 ◽  
Vol 61 (Suppl 1) ◽  
pp. i6-i17 ◽  
Author(s):  
Maura Dandri ◽  
Stephen Locarnini
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Immune Responses ◽  
Current Knowledge ◽  
Hbv Infection ◽  
Infected Hepatocyte ◽  
Hbv Replication ◽  
Chronic Hepatitis B Virus ◽  
B Virus ◽  
Important Host

Chronic hepatitis B virus (HBV) infection remains a major health burden and the main risk factor for the development of hepatocellular carcinoma worldwide. However, HBV is not directly cytopathic and liver injury appears to be mostly caused by repeated attempts of the host's immune responses to control the infection. Recent studies have shown that the unique replication strategy adopted by HBV enables it to survive within the infected hepatocyte while complex virus–host interplays ensure the virus is able to fulfil its replication requirements yet is still able to evade important host antiviral innate immune responses. Clearer understanding of the host and viral mechanisms affecting HBV replication and persistence is necessary to design more effective therapeutic strategies aimed at improving the management of patients with chronic HBV infection to eventually achieve viral eradication. This article focuses on summarising the current knowledge of factors influencing the course of HBV infection, giving emphasis on the use of novel assays and quantitative serological and intrahepatic biomarkers as tools for predicting treatment response and disease progression.

scholarly journals IFI16 induces inflammation in Hepatitis B Virus-Associated Glomerulonephritis by Regulating the Caspase-1 /IL-1ß pathway

2021 ◽  
Author(s):  
Li Liu ◽  
Xiuhua Zhao ◽  
Shuangshuang Xie ◽  
Cheng Li ◽  
Yue Guo ◽  
...  
Keyword(s):  
Immune Response ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cell Line ◽  
293T Cell ◽  
Hbv Infection ◽  
Caspase 1 ◽  
B Virus

Abstract Aims & backgroundIFI16 plays an important role in innate immunity against invasive microbial infection by sensing double-stranded DNA viruses due to caspase-1-dependent inflammasome activation and subsequent maturation and secretion of IL-1β. However, the role of IFI16 in regulating the immune response to viruses in Hepatitis B Virus-Associated Glomerulonephritis(HBV-GN), especially in sensing the hepatitis B virus (HBV), has not been determined. In this study,, we investigated the inflammatory role of IFI16 in HBV-GN.MethodsA total of 75 kidney tissues including 50 HBV-GN and 25 chronic glomerulonephritis (CCN) were collected to determine expression of IFI16, Caspase-1, and IL-1𝛽 by immunohistochemistry (IHC), and then the correlation between them was analyzed. In vitro, the overexpression or knockdown of IFI16 in regulating the immune response to HBV infection in the human glomerular mesangial (HGM) cell line and HEK-293T cell line. Quantitative Real-time PCR and western blotting were used to determine the expression of IFI16, Caspase-1 and IL-1β. The role effect of IFI16 in vivo was further investigated.ResultsIFI16 expression in HBV-GN biopsies (80.0%) was significantly higher than in CGN (24.0%) and was positively correlated with caspase-1 and IL-1𝛽 expression in HBV-GN. In vitro, over expression of IFI16 increased caspase-1 and IL-1𝛽 expression in HBV-infected HGM and HEK-293T cell lines, whereas knockdown of IFI16 mRNA by siRNA resulted in downregulation of the caspase-1 and IL-1𝛽 expression in both cell lines.ConclusionsThe elevation of IFI16 during HBV infection or replication may contribute to renal damage due to inflammation, thus providing a putative therapeutic target and a new avenue for studying the pathogenesis of HBV-GN.

scholarly journals Sirtuins as Potential Therapeutic Targets for Hepatitis B Virus Infection

2021 ◽  
Vol 8 ◽  
Author(s):  
Fanyun Kong ◽  
Qi Li ◽  
Fulong Zhang ◽  
Xiaocui Li ◽  
Hongjuan You ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Histone Deacetylases ◽  
Molecular Mechanisms ◽  
Hbv Infection ◽  
Viral Propagation ◽  
Therapeutic Modalities ◽  
Cellular Processes ◽  
Hbv Replication ◽  
B Virus

Sirtuins (SIRTs) are well-known histone deacetylases that are capable of modulating various cellular processes in numerous diseases, including the infection of hepatitis B virus (HBV), which is one of the primary pathogenic drivers of liver cirrhosis and hepatocellular carcinoma. Mounting evidence reveals that HBV can alter the expression levels of all SIRT proteins. In turn, all SIRTs regulate HBV replication via a cascade of molecular mechanisms. Furthermore, several studies suggest that targeting SIRTs using suitable drugs is a potential treatment strategy for HBV infection. Here, we discuss the molecular mechanisms associated with SIRT-mediated upregulation of viral propagation and the recent advances in SIRT-targeted therapy as potential therapeutic modalities against HBV infection.

scholarly journals RNA-Binding Motif Protein 24 (RBM24) Is Involved in Pregenomic RNA Packaging by Mediating Interaction between Hepatitis B Virus Polymerase and the Epsilon Element

2019 ◽  
Vol 93 (6) ◽  
Author(s):  
Yongxuan Yao ◽  
Bo Yang ◽  
Yingshan Chen ◽  
Hui Wang ◽  
Xue Hu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Rna Binding ◽  
Binding Activity ◽  
Hbv Infection ◽  
Binding Motif ◽  
Independent Manner ◽  
Stem Loop ◽  
Hbv Replication ◽  
B Virus

ABSTRACTEncapsidation of pregenomic RNA (pgRNA) is a crucial step in hepatitis B virus (HBV) replication. Binding by viral polymerase (Pol) to the epsilon stem-loop (ε) on the 5′-terminal region (TR) of pgRNA is required for pgRNA packaging. However, the detailed mechanism is not well understood. RNA-binding motif protein 24 (RBM24) inhibits core translation by binding to the 5′-TR of pgRNA. Here, we demonstrate that RBM24 is also involved in pgRNA packaging. RBM24 directly binds to the lower bulge of ε via RNA recognition submotifs (RNPs). RBM24 also interacts with Pol in an RNA-independent manner. The alanine-rich domain (ARD) of RBM24 and the reverse transcriptase (RT) domain of Pol are essential for binding between RBM24 and Pol. In addition, overexpression of RBM24 increases Pol-ε interaction, whereas RBM24 knockdown decreases the interaction. RBM24 was able to rescue binding between ε and mutant Pol lacking ε-binding activity, further showing that RBM24 mediates the interaction between Pol and ε by forming a Pol-RBM24-ε complex. Finally, RBM24 significantly promotes the packaging efficiency of pgRNA. In conclusion, RBM24 mediates Pol-ε interaction and formation of a Pol-RBM24-ε complex, which inhibits translation of pgRNA and results in pgRNA packing into capsids/virions for reverse transcription and DNA synthesis.IMPORTANCEHepatitis B virus (HBV) is a ubiquitous human pathogen, and HBV infection is a major global health burden. Chronic HBV infection is associated with the development of liver diseases, including fulminant hepatitis, hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. A currently approved vaccine can prevent HBV infection, and medications are able to reduce viral loads and prevent liver disease progression. However, current treatments rarely achieve a cure for chronic infection. Thus, it is important to gain insight into the mechanisms of HBV replication. In this study, we found that the host factor RBM24 is involved in pregenomic RNA (pgRNA) packaging and regulates HBV replication. These findings highlight a potential target for antiviral therapeutics of HBV infection.

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